Identify the true statement. choose one: a. the angle of repose is the steepest angle at which unconsolidated sediments can sit without slipping downhill. b. lahars are mudflows that have been triggered by earthquake shaking. c. slow movement of unconsolidated material downslope is called a turbidity current. d. the head scarp of a slump is found at the base of the slump block.

A. The angle of repose is the steepest angle at which unconsolidated sediments can sit without slipping downhill

Explanation:

The angle of repose is the steepest angle at which unconsolidated sediment can be piled without sliding downward. The angle is also known as critical angle . At this angle the unconsolidated sediments are at the verge of slumping . The angle between the surface of the piled sediments and the horizontal surface is the angle of the repose. At this angle the unconsolidated sediments have reached it limit of accommodating more materials unless it will slump downward.

The make up of the unconsolidated sediments can affect the angle of repose as rounded and fined gained rocks cannot be piled as rough texture d rock materials. The angle of repose can also be affected by the amount of solvents in the sediment. Various rocks sediments possess different angle of repose. Same sediment material can possess different angle of repose if the water contents varies .Example, the angle of repose for sand varies depending on the water contents. The true statement is option A.

The picture above illustrate the angle of repose.